High severity · published Sep 17, 2026
CVE-2026-54580
mport index decompression can leave partial or corrupt index data after zstd failures
8.3
CVSS
0.3%
EPSS
No
On KEV
Description
mport is the MidnightBSD Package Manager. Prior to 2.7.8, libmport/util.c did not make every truncated, corrupt, or failed zstd stream fatal in mport_decompress_zstd(), and libmport/fetch.c did not consistently propagate those failures to index-fetch callers. A malicious or faulty mirror could supply compressed package index data that caused ZSTD_decompressStream() or an output write to fail while leaving partial index output available for later use, resulting in package-index integrity loss or denial of service. This issue is fixed in version 2.7.8.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MP
mport · MidnightBSD
< 2.7.8 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54580
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54580
github.com
https://github.com/MidnightBSD/mport/commit/b3e11ba078351402082a881209ee6fda5d332e3d
github.com
https://github.com/MidnightBSD/mport/pull/135
github.com
https://github.com/MidnightBSD/mport/releases/tag/2.7.8
github.com
https://github.com/MidnightBSD/mport/security/advisories/GHSA-ffqj-j42r-747w
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